Original

Intensive Care Medicine

, Volume 34, Issue 11, pp 2026-2034

First online:

Proportional assist ventilation with load-adjustable gain factors in critically ill patients: comparison with pressure support

  • Nektaria XirouchakiAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , Eumorfia KondiliAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , Katerina VaporidiAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , George XirouchakisAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , Maria KlimathianakiAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , George GavriilidisAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , Evi AlexandopoulouAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , Maria PlatakiAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
  • , Christina AlexopoulouAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete
    • , Dimitris GeorgopoulosAffiliated withIntensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete Email author 

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Abstract

Objectives

It is not known if proportional assist ventilation with load-adjustable gain factors (PAV+) may be used as a mode of support in critically ill patients. The aim of this study was to examine the effectiveness of sustained use of PAV+ in critically ill patients and compare it with pressure support ventilation (PS).

Design and setting

Randomized study in the intensive care unit of a university hospital.

Methods

A total of 208 critically ill patients mechanically ventilated on controlled modes for at least 36 h and meeting certain criteria were randomized to receive either PS (n = 100) or PAV+ (n = 108). Specific written algorithms were used to adjust the ventilator settings in each mode. PAV+ or PS was continued for 48 h unless the patients met pre-defined criteria either for switching to controlled modes (failure criteria) or for breathing without ventilator assistance.

Results

Failure rate was significantly lower in PAV+ than that in PS (11.1 vs. 22.0%, P = 0.040, OR 0.443, 95% CI 0.206–0.952). The proportion of patients exhibiting major patient–ventilator dyssynchronies at least during one occasion and after adjusting the initial ventilator settings, was significantly lower in PAV+ than in PS (5.6 vs. 29.0%, P < 0.001, OR 0.1, 95% CI 0.06–0.4). The proportion of patients meeting criteria for unassisted breathing did not differ between modes.

Conclusions

PAV+ may be used as a useful mode of support in critically ill patients. Compared to PS, PAV+ increases the probability of remaining on spontaneous breathing, while it considerably reduces the incidence of patient–ventilator asynchronies.

Keywords

Controlled modes Assisted modes Patient–ventilator interaction